/*
 * Copyright 2016-2018 shardingsphere.io.
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * </p>
 */

package com.zmn.oms.persistence.algorithm;
import io.shardingsphere.api.algorithm.sharding.PreciseShardingValue;
import io.shardingsphere.api.algorithm.sharding.standard.PreciseShardingAlgorithm;

import java.util.Collection;

/**
 * HASH取模
 */
public class HashModuloShardingTableAlgorithm implements PreciseShardingAlgorithm {


    private int modulo = 8;

    public HashModuloShardingTableAlgorithm() {
    }


    /**
     * @param modulo 模数
     */
    public HashModuloShardingTableAlgorithm(int modulo) {
        this.modulo = modulo;
    }

    public int getModulo() {
        return modulo;
    }

    @Override
    public String doSharding(final Collection tableNames, final PreciseShardingValue shardingValue) {
        Object obj = shardingValue.getValue();
        long code = Math.abs(obj.hashCode());
        for (Object each : tableNames) {
            if (each.toString().endsWith(code % modulo + "")) {
                return (String) each;
            }
        }
        throw new UnsupportedOperationException();
    }

}
